JPH04281178A - Vacuum drying treatment device - Google Patents

Abstract

PURPOSE:To prevent the wasteful consumption of heat energy by a method wherein a waste heat recovering device, recovering the waste heat of water vapor passing through a water vapor discharging passage into refrigerant in a refrigerant circulating passage to condense the water vapor, is provided to condense the water vapor generated in a drier and discharge it as drain water. CONSTITUTION:Matters to be dried, such as garbage and the like, is sealed in a drying machine 1 and the inside of the drying machine 1 is evacuated by driving a water- sealed vacuum pump 3 while a heat pump 8 is driven to generate cold heat. The generated cold heat is exchanged with the heat in a refrigerant circulating passage 5 by the evaporator 10 of a chiller unit 11 to cool the water through heat exchange while the warm heat of the heat pump 8 is exchanged with hot water in a heat medium circulating passage 4 by a condenser 9 through heat exchange to heat a drier by the hot-water. The drying machine 1 is heated by the hot-water through a heat exchanger 6 for heating the drier to heat the matters to be dried and evaporate the moisture thereof while the generated water vapor is sucked into a water vapor discharging passage 2 by the vacuum pump 3 and heat exchange is effected in a waste heat recovering device 7 between cold water in the evaporator 10 to discharge it as drain water.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum drying apparatus.

0002

2. Description of the Related Art As shown in FIG. 2, a conventional vacuum drying processing apparatus is equipped with a heating device 20 such as an electric heater, and a vacuum pump 22 is connected to a pressure-resistant airtight container-shaped dryer 1 which is kept warm by a heat insulating material 21. There is.

[0003] This device evaporates the water content of the material to be dried stored in the dryer 1 by reducing the pressure inside the dryer 1 using a vacuum pump 22 to lower the boiling point of the water in the dryer 1. The heating device 20 supplies the thermal energy necessary for the evaporation.

0004

[Problem to be solved by the invention] However, when the upper space of the dryer is filled with evaporated water vapor and becomes saturated,
Since water vapor no longer evaporates and boiling stops, in the conventional vacuum drying processing equipment mentioned above, it is necessary to keep operating the vacuum pump during the drying process in order to discharge the evaporated water vapor. The resulting heat energy is dissipated into the atmosphere, resulting in wasted energy consumption.

The present invention has been made in view of the above-mentioned problems of the prior art, and its object is to provide a vacuum drying apparatus that does not waste heat energy.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the vacuum drying processing apparatus of the present invention includes a pressure-resistant airtight container-shaped dryer, and a water vapor discharge passage that is taken out from the top of the dryer and released to the atmosphere. , a water ring vacuum pump installed in the middle of the water vapor discharge passage, a heat medium circulation path for circulating the heat medium, a refrigerant circulation path for circulating the refrigerant, and a heat medium circulation path provided in the dryer. A heat exchanger for heating the dryer heats the material by exchanging the heat of the heat medium with the material to be dried in the dryer, and a water vapor discharge passage passes through the water vapor discharge passage on the upstream side of the water ring vacuum pump. a waste heat recovery device that collects the waste heat of water vapor into a refrigerant flowing in a refrigerant circulation path to condense the water vapor;
It includes a heat pump, a condenser that exchanges heat generated by the heat pump with a heat medium flowing in a heat medium circulation path, and an evaporator that exchanges heat generated by the heat pump with a refrigerant flowing in a refrigerant circulation path.

[0007]

[Operation] In the vacuum drying apparatus constructed as described above, most of the water vapor generated inside the dryer is condensed to reduce its volume and discharged as drain water mixed with some water vapor.

[0008] Furthermore, the thermal energy consumed for evaporation inside the dryer is recovered from the waste heat of water vapor and recycled. The heat dissipated by the water vapor mixed with the drain water and discharged is covered by the cooling heat of the heat pump compressor, and the balance of heat balance is maintained.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In the figure, 1 is a dryer configured in the form of a pressure-resistant airtight container;
1 is a heat pump type chiller unit, and the dryer 1 is provided with an input port 12 for inputting the material to be dried and an outlet 13 for taking out the material to be dried, and a stirring device 14 for stirring the material to be dried in order to promote drying. and an auxiliary heating device 15.

The stirring device 14 consists of a screw 14a and a motor 14b that rotates the screw 14a. In addition, the peripheral edge is formed to have a slight distance from the inner circumferential surface of the side wall of the dryer 1, and the distance gradually increases as it extends upward. The auxiliary heating device 15 will be described later.

Further, the dryer 1 has a water vapor discharge passage 2 taken out from the top and a water jacket 6 provided on the side wall.

The end of the water vapor discharge passage 2 is open to the atmosphere, and a waste heat recovery device 7 and a water ring type vacuum pump 3 are interposed in the middle.

A heat medium circulation path 4 in which a circulation pump 16 is interposed is connected to the water jacket 6 . Therefore water jacket 6
constitutes a dryer heating heat exchanger that heats the dryer 1 by exchanging heat with the dryer 1 through a circulating heat medium. Note that the heating medium is hot water.

The waste heat recovery device 7 is provided in the water vapor discharge passage 2 between the dryer 1 and the water ring type vacuum pump 3, and has the water vapor discharge passage 2 passed therein in a meandering manner, and also connects the circulation pump 1 with the water vapor discharge passage 2.
A refrigerant circulation path 5 with a refrigerant circuit 7 interposed therebetween is connected.

The water ring type vacuum pump 3 has a conventionally well-known structural form in which the main body is composed of a circular casing and an impeller eccentrically mounted within the casing, and an appropriate amount of water is placed in the casing. When the impeller rotates, the water creates a circular water film concentric with the casing due to centrifugal force, which creates a sealed space between the water film and the adjacent blades, and as the impeller rotates, the space expands. The volume changes, and suction, compression, and ejection are performed continuously.

On the other hand, the heat pump type chiller unit 11 has a heat pump 8 in which a compressor 8a and a capillary tube 8b are interposed in a closed circulation pipe filled with a refrigerant such as fluorocarbon, and the compressor 8a and the capillary tube 8b are connected in the flow direction of the refrigerant. condenser 9 between
, an evaporator 10 is provided between the capillary tube 8b and the compressor 8a, and the heat medium circulation path 4 and the refrigerant circulation path 5 are provided passing through the inside of the condenser 9 and the inside of the evaporator 10, respectively.

[0017] Thus, such a vacuum drying processing apparatus includes a dryer 1.
For example, put materials to be dried, such as food waste, into the dryer and seal it, drive the water ring vacuum pump 3, reduce the pressure inside the dryer 1 until the boiling point of water becomes equal to the outside temperature, and then heat the heat pump 8. When the compressor 8a is driven, the heat pump 8 becomes high pressure between the compressor 8a and the capillary tube 8b due to the passage resistance of the capillary tube 8b, causing condensation of the refrigerant and increasing the temperature. The pressure becomes low and the refrigerant evaporates, causing the temperature to drop.

The cold heat generated by the heat pump 8 is exchanged with the water circulating through the refrigerant circulation path 5 in the evaporator 10 of the chiller unit 11 to absorb the heat of the water and cool the water, and the warm heat of the heat pump 8 is used as a chiller. The condenser 9 of the unit 11 exchanges heat with the hot water circulating through the heat medium circuit 4 to heat the hot water.

The hot water heated in the condenser 9 of the chiller unit 11 flows to the heat exchanger 6 for heating the dryer, and then the hot water is heated in the condenser 9 of the chiller unit 11.
is heated, and the heating energy warms the material to be dried inside the dryer 1 to evaporate water.

[0020] This increases the steam pressure within the dryer 1, and the water vapor within the dryer 1 is sucked into the steam exhaust passage 2 together with the operation of the water ring vacuum pump 3.

On the other hand, the cold water cooled by the evaporator 10 of the chiller unit 11 flows to the waste heat recovery device 7, where waste heat is recovered from the water vapor flowing through the water vapor discharge passage 2 and condensed.

[0022] As a result, the water vapor is reduced in volume and is discharged as drain water via the water ring vacuum pump 3. Therefore, evaporation occurs continuously inside the dryer 1 and the material to be dried is dried.

In this device, the dryer 1 uses the heat of the heat pump 8 indirectly by exchanging heat with water for heating, and the waste heat recovery device 7 uses the heat of the heat pump 8 to recover and condense the waste heat of water vapor. The cold heat of the heat pump 8 is used indirectly by exchanging heat with water. That is, the heat energy consumed for evaporation inside the dryer 1 is recovered by the waste heat recovery device 7, and the heat energy is recovered by the heat pump 8.
It is returned to the original dryer 1 and recycled.

[0024] Since the drain water contains some water vapor, the heat of the water vapor mixed with the drain water and discharged will be dissipated, but the heat will be dissipated by the compressor 8.
Since the cooling heat is added, the heat balance is maintained, and operation is possible without replenishing heat with a heating device such as a gas burner or electric heater.

However, in the final stage of drying, the auxiliary heating device 15 is used if it is necessary to thoroughly dry the material to be dried.

This auxiliary heating device 15 is a tube-type gas burner that generates far infrared rays, and in addition to the above case, it is temporarily used in winter to prevent the cold water temperature from becoming too low at the initial stage of operation and becoming inoperable. Sometimes it is used.

If the auxiliary heating device 15 is used in combination, the balance of thermal energy sent to the dryer 1 and the waste heat recovery device 7 will be disrupted, so an auxiliary radiator (not shown) consisting of a fan or the like is installed in the heat medium circulation path 4. to release excess heat.

[0028] Depending on the material to be dried, such as garbage containing a large amount of water, it may be sufficient to dry it by removing only the moisture, and the drying equipment used for drying such material may require the above-mentioned support. There is no need to intentionally equip the heating device 15.

Although the vacuum drying apparatus of the present invention described above can be used to dry any kind of material, it is suitable for drying at a relatively low temperature and in a short period of time, and is particularly suitable for processing food waste. It is very effective when used as a laundry drying device.

That is, if garbage is processed using the apparatus of the present invention, 1. Since it dries at a low temperature, it can be put into a plastic container or the like immediately after drying, making it easy to collect. 2. It is lighter because there is no water. 3. Since the inside of the device is in a near-vacuum state, no spoilage occurs and it is hygienic. 4. Since no chemicals are used, the collected waste can be reused as fertilizer or feed, and can be easily incinerated. 5. Since the water that is evaporated and removed is distilled water, there is no need to worry about water pollution even if it is released as is. It has excellent effects such as

[0031] Furthermore, if laundry is dried using this device, 1. Since it dries at a low temperature, there is no risk of damaging the fabric due to drying. 2. It is more efficient and can significantly reduce the time required for drying compared to conventional laundry dryers. 3. Since no water vapor is dissipated, there is no need to provide an exhaust pipe or the like. There are advantages such as

[0032]

[Effects] Since the present invention is constructed as described above, energy is not wasted by dissipating into the atmosphere and is very economical.

Furthermore, since the water vapor evaporated from the material to be dried is condensed in the waste heat recovery device to reduce its volume, the drainage efficiency of the water ring vacuum pump is increased and a small pump can be used.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a vacuum drying processing apparatus showing an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing an example of a conventional vacuum drying processing apparatus.

[Explanation of symbols]

1 Dryer
2 Steam exhaust passage 3 Water ring vacuum pump
4 Heat medium circulation path 5 Refrigerant circulation path
6 Heat exchanger for heating the dryer

Claims (1)

[Claims] Claim 1: A dryer in the form of a pressure-resistant airtight container, a water vapor discharge passage taken out from the top of the dryer and opened to the atmosphere, a water ring type vacuum pump interposed in the water vapor discharge passage, and a heat medium. A heat medium circulation path for circulating and flowing a refrigerant, a refrigerant circulation path for circulating and flowing a refrigerant, and a heat medium provided in the dryer and flowing through the heat medium circulation path is exchanged with the material to be dried in the dryer to dry the material. and a heat exchanger for heating the dryer, and a waste heat exchanger that condenses water vapor by recovering the waste heat of the water vapor passing through the water vapor discharge passage into the refrigerant flowing in the refrigerant circulation path, on the upstream side of the water ring vacuum pump in the water vapor discharge passage. A heat recovery device, a heat pump,
Vacuum drying characterized by comprising: a condenser that exchanges heat generated by a heat pump with a heat medium flowing in a heat medium circulation path; and an evaporator that exchanges heat generated by the heat pump with a refrigerant flowing in a refrigerant circulation path. Processing equipment.